Search or filter publications

Filter by type:

Filter by publication type

Filter by year:

to

Results

  • Showing results for:
  • Reset all filters

Search results

  • Journal article
    Douglas J, Akkar S, Ameri G, Bard P-Y, Bindi D, Bommer JJ, Bora SS, Cotton F, Derras B, Hermkes M, Kuehn NM, Luzi L, Massa M, Pacor F, Riggelsen C, Sandikkaya MA, Scherbaum F, Stafford PJ, Traversa Pet al., 2014,

    Comparisons among the five ground-motion models developed using RESORCE for the prediction of response spectral accelerations due to earthquakes in Europe and the Middle East

    , BULLETIN OF EARTHQUAKE ENGINEERING, Vol: 12, Pages: 341-358, ISSN: 1570-761X
  • Journal article
    Elghazouli AY, Kumar M, Stafford PJ, 2014,

    Prediction and optimisation of seismic drift demands incorporating ground motion frequency content

    , BULLETIN OF EARTHQUAKE ENGINEERING, Vol: 12, Pages: 255-276, ISSN: 1570-761X
  • Journal article
    Rossetto T, D'Ayala D, Gori F, Persio R, Han J, Novelli V, Wilkinson SM, Alexander D, Hill M, Stephens S, Kontoe S, Elia G, Verrucci E, Vicini A, Shelley W, Foulser-Piggott Ret al., 2014,

    The value of multiple earthquake missions: the EEFIT L'Aquila Earthquake experience

    , BULLETIN OF EARTHQUAKE ENGINEERING, Vol: 12, Pages: 277-305, ISSN: 1570-761X
  • Journal article
    Bora SS, Scherbaum F, Kuehn N, Stafford Pet al., 2014,

    Fourier spectral- and duration models for the generation of response spectra adjustable to different source-, propagation-, and site conditions

    , BULLETIN OF EARTHQUAKE ENGINEERING, Vol: 12, Pages: 467-493, ISSN: 1570-761X
  • Journal article
    Jordan JR, Holland PR, Jenkins A, Piggott MD, Kimura Set al., 2014,

    Modeling ice-ocean interaction in ice-shelf crevasses

    , JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, Vol: 119, Pages: 995-1008, ISSN: 2169-9275
  • Journal article
    van Reeuwijk M, Holzner M, 2014,

    The turbulence boundary of a temporal jet

    , Journal of Fluid Mechanics, Vol: 739, Pages: 254-275, ISSN: 0022-1120

    We examine the structure of the turbulence boundary of a temporal plane jet at Re=5000 using statistics conditioned on the enstrophy. The data is obtained by direct numerical simulation and threshold values span 24 orders of magnitude, ranging from essentially irrotational fluid outside the jet to fully turbulent fluid in the jet core. We use two independent estimators for the local entrainment velocity vn based on the enstrophy budget. The data show clear evidence for the existence of a viscous superlayer (VSL) that envelopes the turbulence. The VSL is a nearly one-dimensional layer with low surface curvature. We find that both its area and viscous transport velocity adjust to the imposed rate of entrainment so that the integral entrainment flux is independent of threshold, although low-Reynolds-number effects play a role for the case under consideration. This threshold independence is consistent with the inviscid nature of the integral rate of entrainment. A theoretical model of the VSL is developed that is in reasonably good agreement with the data and predicts that the contribution of viscous transport and dissipation to interface propagation have magnitude 2vn and −vn , respectively. We further identify a turbulent core region (TC) and a buffer region (BR) connecting the VSL and the TC. The BR grows in time and inviscid enstrophy production is important in this region. The BR shows many similarities with the turbulent–non-turbulent interface (TNTI), although the TNTI seems to extend into the TC. The average distance between the TC and the VSL, i.e. the BR thickness is about 10 Kolmogorov length scales or half a Taylor length scale, indicating that intense turbulent flow regions and viscosity-dominated regions are in close proximity.
  • Journal article
    Mannie AS, Jackson CAL, Hampson GJ, 2014,

    Structural controls on the stratigraphic architecture of net-transgressive shallow-marine strata, Middle-to-Upper Jurassic, Egersund Basin, Norwegian North Sea

    , Basin Research, Vol: 26, Pages: 675-700

    In this study we integrate 3D seismic reflection, wireline log, biostratigraphic and core data from the Egersund Basin, Norwegian North Sea to determine the impact of syn-depositional salt movement and associated growth faulting on the sedimentology and stratigraphic architecture of the Middle-to-Upper Jurassic, net-transgressive, syn-rift succession. Borehole data indicate that Middle-to-Upper Jurassic strata consist of low-energy, wave-dominated offshore and shoreface deposits, and coal-bearing coastal plain deposits. These deposits are arranged in four parasequences that are aggradationally to retrogradationally stacked to form a net-transgressive succession that is up to 150 m thick, at least 20 km in depositional strike (SW-NE) extent, and >70 km in depositional dip (NW-SE) extent. In this rift-margin location, changes in thickness but not facies are noted across active salt structures. Abrupt facies changes, from shoreface sandstones to offshore mudstones, only occur across large displacement, basement-involved normal faults. Comparisons to other tectonically active salt-influenced basins suggest that facies changes across syn-depositional salt structures are observed only where expansion indices are >2. Subsidence between salt walls resulted in local preservation of coastal-plain deposits that cap shoreface parasequences, which were locally removed by transgressive erosion in adjacent areas of lower subsidence. The depositional dip that characterises the Egersund Basin is unusual and likely resulted from its marginal location within the evolving North Sea rift and an extra-basinal sediment supply from the Norwegian mainland.
  • Journal article
    Bell RE, Jackson CAL, Elliott GM, Gawthorpe RL, Sharp IR, Michelsen L, Bell R, Jackson CA-L, Elliott G, Gawthorpe R, Sharp IR, Michelsen Let al., 2014,

    Insights into the development of major rift-related unconformities from geologically constrained subsidence modelling: Halten Terrace, offshore mid Norway

    , Basin Research, Vol: 26, Pages: 203-224

    Due to the effects of sediment compaction, thermal subsidence and ‘post-rift’ fault reactivation, the present-day geometry of buried, ancient rift basins may not accurately reflect the geometry of the basin at any stage of its syn-rift evolution. An understanding of the geometry of a rift basin through time is crucial for resolving the dynamics of continental rifting and in assessing the hydrocarbon prospectivity of such basins. In this study, we have restored the Late Jurassic–Early Cretaceous geometry of the southern Halten Terrace, offshore mid Norway, using a combination of well log- and core-derived, sedimentological and stratigraphic data, seismic-stratigraphic observations and reverse subsidence modelling. This integrated geological and geophysical approach has allowed the large number of input parameters involved in flexural backstripping and post-rift thermal subsidence modelling to be constrained. We have thus been able to determine the regional structure of the basin at the end of the Late Jurassic–Early Cretaceous rift phase and the associated amount of crustal stretching. Our basin geometry reconstructions reveal that, during the latest syn-rift period in the Late Jurassic–Early Cretaceous, the Halten Terrace was characterized by a series of isolated depocentres, located between footwall islands, which were not connected into a single depocentre until the Late Cretaceous (Coniacian). We show that two major unconformities, which are now vertically offset by ca. 2 km and located ca. 60 km apart, formed at similar subaerial elevations in the Late Jurassic–Early Cretaceous and were subsequently vertically offset by thermally induced tilting of the basin margin. Cretaceous sediments were deposited in a single, relatively unconfined basin in water depths of 1–1.5 km. The β profile that best restores palaeobathymetry to match our geological constraints is the same as that derived from summing visible post-Late Tri
  • Journal article
    Alves TM, Bell RE, Jackson CA-L, Minshull TA, Alves TM, Bell RE, Jackson CAL, Minshull TAet al., 2014,

    Deep-water continental margins: geological and economic frontiers

    , Basin Research, Vol: 26, Pages: 3-9

    Deep-water margins have been the focus of considerable research during the past decade. They comprise vast, underexplored regions, in which only recently have improvements in seismic imaging and drilling technology allowed the discovery of significant hydrocarbon accumulations. This volume comprises of a series of manuscripts based on studies from continental margins bordering India, East Africa, Australia, China, Norway, the United Kingdom, Iberia, Newfoundland, the southern US, West Africa and Brazil, thus offering a global perspective on the evolution and economic significance of deep-water margins. The articles in this volume examine: (i) the quantification of extension and hyperextension in distal parts of continental margins, and their relationship with regional subsidence, (ii) the importance of magmatism in the structural and thermal evolution of rifted continental margins, (iii) the processes driving and the significance of regional exhumation during and after syn-rift stretching, (iv) the tectonic setting of salt basins and (v) depositional patterns along deep-water margins. To complement this work, we present a personal view of some of the specific questions that need to be addressed in the next few years of deep-water continental margin research.
  • Journal article
    Magee C, Jackson CAL, Schofield N, Magee C, Jackson CA-L, Schofield Net al., 2014,

    Diachronous sub-volcanic intrusion along deep-water margins: insights from the Irish Rockall Basin

    , Basin Research, Vol: 26, Pages: 85-105

    The movement of magma in sedimentary basins often occurs through an extensive and interconnected complex of sills. Field-, modelling-, and seismic reflection-based studies indicate that the emplacement of shallow-level sills is commonly accommodated by the formation of forced folds, which may be expressed at the free surface and onlapped by younger strata. If the age of these onlapping strata can be constrained, important insights can be gained into the timing of magma emplacement and associated regional, tectono-magmatic events. Previous studies have focused on isolated intrusions that are overlain by an individual forced fold formed during a single tectono-magmatic event. However, the structure and evolution of ‘compound’ folds developed above stacked, interconnected sills, and what they may reveal about polyphase intrusive events has not been investigated. In this study, we use 3D seismic reflection data from the Irish Rockall Basin, offshore western Ireland, to constrain the structural style and emplacement history of a sill complex that contains 82 seismically resolved intrusions. Individual forced folds, <41 km2 in plan view and with mean fold amplitudes of 111 m, are developed above single intrusions. However, where sills are stacked, broader (100–244 km2), larger amplitude (mean of 296 m) compound folds occur following the coalescence of individual folds. Stratigraphic onlap and truncation observed within the folds throughout the Palaeocene-to-Middle Eocene succession, indicates that emplacement and forced folding initiated at the end Maastrichtian and lasted for ca. 15 Ma, before ceasing near the end of the Ypresian. We demonstrate (i) intrusion-induced forced folds evolve dynamically and can form broad areas of sustained local uplift, and (ii) that the formation of sill complexes within the upper crust may occur over prolonged time periods. This study also highlights the importance of seismic reflection data to understanding the struct
  • Journal article
    Zhang C, Yang ZX, Nguyen GD, Jardine RJ, Einav Iet al., 2014,

    Theoretical breakage mechanics and experimental assessment of stresses surrounding piles penetrating into dense silica sand

    , GEOTECHNIQUE LETTERS, Vol: 4, Pages: 11-16, ISSN: 2049-825X
  • Journal article
    Bierman PR, Corbett LB, Graly JA, Neumann TA, Lini A, Crosby BT, Rood DHet al., 2014,

    Preservation of a preglacial landscape under the center of the greenland ice sheet

    , Science, Vol: 344, Pages: 402-405, ISSN: 0036-8075

    Continental ice sheets typically sculpt landscapes via erosion; under certain conditions, ancient landscapes can be preserved beneath ice and can survive extensive and repeated glaciation. We used concentrations of atmospherically produced cosmogenic beryllium-10, carbon, and nitrogen to show that ancient soil has been preserved in basal ice for millions of years at the center of the ice sheet at Summit, Greenland. This finding suggests ice sheet stability through the Pleistocene (i.e., the past 2.7 million years). The preservation of this soil implies that the ice has been nonerosive and frozen to the bed for much of that time, that there was no substantial exposure of central Greenland once the ice sheet became fully established, and that preglacial landscapes can remain preserved for long periods under continental ice sheets.
  • Journal article
    Matmon A, Fink D, Davis M, Niedermann S, Rood D, Frumkin Aet al., 2014,

    Unraveling rift margin evolution and escarpment development ages along the Dead Sea fault using cosmogenic burial ages

    , Quaternary Research (United States), Vol: 82, Pages: 281-295, ISSN: 0033-5894

    The Dead Sea fault (DSF) is one of the most active plate boundaries in the world. Understanding the Quaternary history and sediments of the DSF requires investigation into the Neogene development of this plate boundary. DSF lateral motion preceded significant extension and rift morphology by ~10Ma. Sediments of the Sedom Formation, dated here between 5.0±0.5Ma and 6.2-2.1+infMa, yielded extremely low 10Be concentrations and 26Al is absent. These reflect the antiquity of the sediments, deposited in the Sedom Lagoon, which evolved in a subdued landscape and was connected to the Mediterranean Sea. The base of the overlying Amora Formation, deposited in the terminal Amora Lake which developed under increasing relief that promoted escarpment incision, was dated at 3.3-0.8+0.9Ma. Burial ages of fluvial sediments within caves (3.4±0.2Ma and 3.6±0.4Ma) represent the timing of initial incision. Initial DSF topography coincides with the earliest Red Sea MORB's and the East Anatolian fault initiation. These suggest a change in the relative Arabian-African plate motion. This change introduced the rifting component to the DSF followed by a significant subsidence, margin uplift, and a reorganization of relief and drainage pattern in the region resulting in the topographic framework observed today. © 2014 University of Washington.
  • Journal article
    D'Arcy M, Whittaker AC, 2014,

    Geomorphic constraints on landscape sensitivity to climate in tectonically active areas

    , Geomorphology, Vol: 204, Pages: 366-381

    The geomorphology of fluvial landscapes is known to record information about uplift rate, spatial patterns of faulting, and tectonic history. Data is far less available when addressing the sensitivity of common geomorphological metrics, such as channel steepness, to climatic boundary conditions. We test the relationship between channel steepness and precipitation rate by measuring a large number of channels in different mountainous areas. These regions exhibit a tenfold variation in precipitation rate between them (~ 100-1000 mm y- 1) but have similar uplift rates, allowing the tectonic variable to be controlled. By accounting for the orographic coupling of rainfall with uplifted topography, we find that channel steepness is significantly suppressed by higher precipitation rates in a measurable way that conforms to simple stream power erosion laws and empirical constraints on their parameters. We demonstrate this using modern and estimated glacial precipitation rates; and climate emerges as an important, quantifiable control on channel geometry. These findings help to explain why highly variable measurements of channel steepness are reported from different locations and provide important empirical constraints on how climate shapes tectonically active landscapes.
  • Journal article
    Monroy R, Zdravkovic L, Ridley AM, 2014,

    Evaluation of an Active System to Measure Lateral Stresses in Unsaturated Soils

    , GEOTECHNICAL TESTING JOURNAL, Vol: 37, ISSN: 0149-6115
  • Journal article
    Hiester HR, Piggott MD, Farrell PE, Allison PAet al., 2014,

    Assessment of spurious mixing in adaptive mesh simulations of the two-dimensional lock-exchange

    , Ocean Modelling, Vol: 73, Pages: 30-44, ISSN: 1463-5003
  • Conference paper
    Bell RE, Henrys S, Sutherland R, Morgan J, Warner M, Barker L, Wallace L, Bangs N, McIntosh Ket al., 2014,

    Characterising the seismic behavior of subduction zones using active source seismic methods

    , SeisMix
  • Conference paper
    Bell RE, Morgan J, Warner M, Bangs Net al., 2014,

    Next-generation seismic experiments:wide-angle, multi-azimuth, three dimensional, full-waveform inversion

    , SEG/AGU Workshop on Advances in Active and Passive “Full Wavefield” Seismic Imaging: From Reservoirs to Plate Tectonics
  • Journal article
    Gasparre A, Hight DW, Coop MR, Jardine RJet al., 2014,

    The laboratory measurement and interpretation of the small strain stiffness of stiff clays

    , Geotechnique, Vol: 64, Pages: 942-953, ISSN: 0016-8505
  • Conference paper
    Jacobs CT, Collins GS, Piggott MD, Kramer SCet al., 2014,

    MULTIPHASE FLOW MODELLING OF EXPLOSIVE VOLCANIC ERUPTIONS USING AN ADAPTIVE UNSTRUCTURED MESH-BASED APPROACH

    , 11th World Congress on Computational Mechanics (WCCM) / 5th European Conference on Computational Mechanics (ECCM) / 6th European Conference on Computational Fluid Dynamics (ECFD), Publisher: INT CENTER NUMERICAL METHODS ENGINEERING, Pages: 7406-7417

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://www.imperial.ac.uk:80/respub/WEB-INF/jsp/search-t4-html.jsp Request URI: /respub/WEB-INF/jsp/search-t4-html.jsp Query String: id=833&limit=20&page=14&respub-action=search.html Current Millis: 1732219607138 Current Time: Thu Nov 21 20:06:47 GMT 2024